1. Field of the Invention
The present invention is related to a novel diagnostic method of autoimmune diseases. More specifically, the present invention is related to a novel method of diagnosing autoimmune diseases by immunologically detecting antibodies to microtubule organizing center (hereinafter, referred to as xe2x80x9cMTOCxe2x80x9d) and/or microtubules extending therefrom and/or accompanying proteins present in human and animal tissues or cells.
2. Description of the Prior Arts
An autoimmune disease, an immune system disorder causing formation of antibodies against endogenous materials and not against foreign materials, may be classified into two categories: systemic rheumatic diseases and organ-specific autoimmune diseases. The systemic rheumatic diseases again may be classified into many kinds of diseases including systemic lupus erythematosus, rheumatoid arthritis, or the like.
Rheumatoid arthritis is a very frequently occurring disease, which is found in 1-5% of the world""s populations. Its typical symptoms include morning stiffness and joint pains of the hands and feet.
Since the etiology of rheumatoid arthritis is still unknown, its successful therapy or accurate diagnosis is not easy.
Until now, the rheumatoid factor has been detected to diagnose rheumatoid arthritis. However, the rheumatoid factor is not detected in all patients with the disease, and furthermore, shows positive results in about 5-20% of normal persons. (ARA Glossary Committee, Dictionary of the rheumatic disease 11, diagnostic testing, p. 17, 1985).
To avoid these problems, anti-keratin, anti-perinuclear factor and anti-RA-33 antibodies were developed. These antibodies contributed in improving the diagnostic specificity of rheumatoid arthritis. However, the sensitivity is still low to use in practice.
In particular, the ANA test (xe2x80x9cAnti-nuclear antibody testxe2x80x9d) has been the most widely used test in diagnosing autoimmune diseases. However, the conventional ANA test employing the HEp-2 cell line is mainly directed to detect systemic lupus erythematosus. Therefore, it is necessary to detect the rheumatoid factor separately in order to diagnose rheumatoid arthritis.
The present inventor had found that a macrophage is more useful than the conventionally used HEp-2 cell to diagnose autoimmune diseases, and succeeded in establishing a macrophage cell line. The established cell line was named xe2x80x9cIT-1xe2x80x9d and was deposited on Jul. 15, 1992, at the Korean Culture Collection of Microorganisms, Yonsei University located in Seoul, Korea, under Accession No. KFCC 10772 according to the Budapest Treaty.
As a result of continuing extensive research, the present inventor surprisingly found that body fluids of patients with rheumatoid arthritis characteristically contain antibodies against microtubule organizing center (xe2x80x9cMTOCxe2x80x9d) and/or microtubules (xe2x80x9cMTxe2x80x9d) extending therefrom.
Thus, an object of the present invention is to provide a method for diagnosing autoimmune diseases with high specificity and sensitivity.
Another object of the present invention is to provide a method for diagnosing autoimmune diseases comprising steps of:
contacting a body fluid sample of a subject suspected to have an autoimmune disease with any living tissue or cell line; and
determining whether or not MTOC and/or MT and/or accompanying proteins have reacted with anti-MTOC-MT antibodies in the body fluid.
The present invention also provides a method for detecting anti-nuclear antibody, anti-cytoplasmic antibody and anti-MTOC-MT antibodies simultaneously by using a tissue or cell.
The present invention further provides a method for diagnosing autoimmune diseases comprising the following steps:
preparing a glass slide, on which a tissue or cell is immobilized;
preparing a body fluid sample of a subject suspected to have an autoimmune disease;
contacting the body fluid sample with the tissue or cell on the glass slide and incubating at a certain temperature for a certain period of time; and
detecting the presence of anti-MTOC-MT antibodies, which respond to the MTOC, MT or accompanying proteins in the tissue or cell.